Added prototype implementation of scala:shell task
Added prototype implementation of scala:shell task

git-svn-id: d8f3215415546ce936cf3b822120ca56e5ebeaa0@787456 13f79535-47bb-0310-9956-ffa450edef68

assaf/buildr,apache/buildr,atoulme/buildr,stewi2/buildr,jpcaruana/buildr,assaf/buildr,jpcaruana/buildr,liamchristopher/buildr,apache/buildr,liamchristopher/buildr,mariusk/buildr-kawa,atoulme/buildr,assaf/buildr,jpcaruana/buildr,liamchristopher/buildr,atoulme/buildr,mariusk/buildr-kawa,apache/buildr,jpcaruana/buildr,apache/buildr,liamchristopher/buildr,mariusk/buildr-kawa,stewi2/buildr,stewi2/buildr,stewi2/buildr